diff options
| -rw-r--r-- | fs/ext4/verity.c | 47 | ||||
| -rw-r--r-- | fs/f2fs/data.c | 2 | ||||
| -rw-r--r-- | fs/f2fs/f2fs.h | 3 | ||||
| -rw-r--r-- | fs/f2fs/verity.c | 47 | ||||
| -rw-r--r-- | fs/verity/enable.c | 8 | ||||
| -rw-r--r-- | fs/verity/fsverity_private.h | 1 | ||||
| -rw-r--r-- | fs/verity/open.c | 1 | ||||
| -rw-r--r-- | fs/verity/verify.c | 34 | ||||
| -rw-r--r-- | include/linux/fsverity.h | 7 |
9 files changed, 137 insertions, 13 deletions
diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c index d0d8a9795dd6..dc5ec724d889 100644 --- a/fs/ext4/verity.c +++ b/fs/ext4/verity.c @@ -342,12 +342,55 @@ static int ext4_get_verity_descriptor(struct inode *inode, void *buf, return desc_size; } +/* + * Prefetch some pages from the file's Merkle tree. + * + * This is basically a stripped-down version of __do_page_cache_readahead() + * which works on pages past i_size. + */ +static void ext4_merkle_tree_readahead(struct address_space *mapping, + pgoff_t start_index, unsigned long count) +{ + LIST_HEAD(pages); + unsigned int nr_pages = 0; + struct page *page; + pgoff_t index; + struct blk_plug plug; + + for (index = start_index; index < start_index + count; index++) { + page = xa_load(&mapping->i_pages, index); + if (!page || xa_is_value(page)) { + page = __page_cache_alloc(readahead_gfp_mask(mapping)); + if (!page) + break; + page->index = index; + list_add(&page->lru, &pages); + nr_pages++; + } + } + blk_start_plug(&plug); + ext4_mpage_readpages(mapping, &pages, NULL, nr_pages, true); + blk_finish_plug(&plug); +} + static struct page *ext4_read_merkle_tree_page(struct inode *inode, - pgoff_t index) + pgoff_t index, + unsigned long num_ra_pages) { + struct page *page; + index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT; - return read_mapping_page(inode->i_mapping, index, NULL); + page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED); + if (!page || !PageUptodate(page)) { + if (page) + put_page(page); + else if (num_ra_pages > 1) + ext4_merkle_tree_readahead(inode->i_mapping, index, + num_ra_pages); + page = read_mapping_page(inode->i_mapping, index, NULL); + } + return page; } static int ext4_write_merkle_tree_block(struct inode *inode, const void *buf, diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index a034cd0ce021..0fa356e94ef5 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1881,7 +1881,7 @@ out: * use ->readpage() or do the necessary surgery to decouple ->readpages() * from read-ahead. */ -static int f2fs_mpage_readpages(struct address_space *mapping, +int f2fs_mpage_readpages(struct address_space *mapping, struct list_head *pages, struct page *page, unsigned nr_pages, bool is_readahead) { diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 5a888a063c7f..059ade83bfb1 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3229,6 +3229,9 @@ int f2fs_reserve_new_block(struct dnode_of_data *dn); int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index); int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from); int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index); +int f2fs_mpage_readpages(struct address_space *mapping, + struct list_head *pages, struct page *page, + unsigned nr_pages, bool is_readahead); struct page *f2fs_get_read_data_page(struct inode *inode, pgoff_t index, int op_flags, bool for_write); struct page *f2fs_find_data_page(struct inode *inode, pgoff_t index); diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c index a401ef72bc82..d7d430a6f130 100644 --- a/fs/f2fs/verity.c +++ b/fs/f2fs/verity.c @@ -222,12 +222,55 @@ static int f2fs_get_verity_descriptor(struct inode *inode, void *buf, return size; } +/* + * Prefetch some pages from the file's Merkle tree. + * + * This is basically a stripped-down version of __do_page_cache_readahead() + * which works on pages past i_size. + */ +static void f2fs_merkle_tree_readahead(struct address_space *mapping, + pgoff_t start_index, unsigned long count) +{ + LIST_HEAD(pages); + unsigned int nr_pages = 0; + struct page *page; + pgoff_t index; + struct blk_plug plug; + + for (index = start_index; index < start_index + count; index++) { + page = xa_load(&mapping->i_pages, index); + if (!page || xa_is_value(page)) { + page = __page_cache_alloc(readahead_gfp_mask(mapping)); + if (!page) + break; + page->index = index; + list_add(&page->lru, &pages); + nr_pages++; + } + } + blk_start_plug(&plug); + f2fs_mpage_readpages(mapping, &pages, NULL, nr_pages, true); + blk_finish_plug(&plug); +} + static struct page *f2fs_read_merkle_tree_page(struct inode *inode, - pgoff_t index) + pgoff_t index, + unsigned long num_ra_pages) { + struct page *page; + index += f2fs_verity_metadata_pos(inode) >> PAGE_SHIFT; - return read_mapping_page(inode->i_mapping, index, NULL); + page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED); + if (!page || !PageUptodate(page)) { + if (page) + put_page(page); + else if (num_ra_pages > 1) + f2fs_merkle_tree_readahead(inode->i_mapping, index, + num_ra_pages); + page = read_mapping_page(inode->i_mapping, index, NULL); + } + return page; } static int f2fs_write_merkle_tree_block(struct inode *inode, const void *buf, diff --git a/fs/verity/enable.c b/fs/verity/enable.c index 9c93c17f1c1c..efc79a2cedf2 100644 --- a/fs/verity/enable.c +++ b/fs/verity/enable.c @@ -8,6 +8,7 @@ #include "fsverity_private.h" #include <crypto/hash.h> +#include <linux/backing-dev.h> #include <linux/mount.h> #include <linux/pagemap.h> #include <linux/sched/signal.h> @@ -86,9 +87,14 @@ static int build_merkle_tree_level(struct file *filp, unsigned int level, return err; } } else { + unsigned long num_ra_pages = + min_t(unsigned long, num_blocks_to_hash - i, + inode->i_sb->s_bdi->io_pages); + /* Non-leaf: hashing hash block from level below */ src_page = vops->read_merkle_tree_page(inode, - params->level_start[level - 1] + i); + params->level_start[level - 1] + i, + num_ra_pages); if (IS_ERR(src_page)) { err = PTR_ERR(src_page); fsverity_err(inode, diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index e74c79b64d88..ab9cfdd8f965 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -50,6 +50,7 @@ struct merkle_tree_params { unsigned int log_arity; /* log2(hashes_per_block) */ unsigned int num_levels; /* number of levels in Merkle tree */ u64 tree_size; /* Merkle tree size in bytes */ + unsigned long level0_blocks; /* number of blocks in tree level 0 */ /* * Starting block index for each tree level, ordered from leaf level (0) diff --git a/fs/verity/open.c b/fs/verity/open.c index 63d1004b688c..e9cdf7d00ed2 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c @@ -102,6 +102,7 @@ int fsverity_init_merkle_tree_params(struct merkle_tree_params *params, /* temporarily using level_start[] to store blocks in level */ params->level_start[params->num_levels++] = blocks; } + params->level0_blocks = params->level_start[0]; /* Compute the starting block of each level */ offset = 0; diff --git a/fs/verity/verify.c b/fs/verity/verify.c index 3e8f2de44667..7fa561c343c2 100644 --- a/fs/verity/verify.c +++ b/fs/verity/verify.c @@ -84,7 +84,8 @@ static inline int cmp_hashes(const struct fsverity_info *vi, * Return: true if the page is valid, else false. */ static bool verify_page(struct inode *inode, const struct fsverity_info *vi, - struct ahash_request *req, struct page *data_page) + struct ahash_request *req, struct page *data_page, + unsigned long level0_ra_pages) { const struct merkle_tree_params *params = &vi->tree_params; const unsigned int hsize = params->digest_size; @@ -117,8 +118,8 @@ static bool verify_page(struct inode *inode, const struct fsverity_info *vi, pr_debug_ratelimited("Level %d: hindex=%lu, hoffset=%u\n", level, hindex, hoffset); - hpage = inode->i_sb->s_vop->read_merkle_tree_page(inode, - hindex); + hpage = inode->i_sb->s_vop->read_merkle_tree_page(inode, hindex, + level == 0 ? level0_ra_pages : 0); if (IS_ERR(hpage)) { err = PTR_ERR(hpage); fsverity_err(inode, @@ -195,7 +196,7 @@ bool fsverity_verify_page(struct page *page) if (unlikely(!req)) return false; - valid = verify_page(inode, vi, req, page); + valid = verify_page(inode, vi, req, page, 0); ahash_request_free(req); @@ -222,21 +223,42 @@ void fsverity_verify_bio(struct bio *bio) { struct inode *inode = bio_first_page_all(bio)->mapping->host; const struct fsverity_info *vi = inode->i_verity_info; + const struct merkle_tree_params *params = &vi->tree_params; struct ahash_request *req; struct bio_vec *bv; struct bvec_iter_all iter_all; + unsigned long max_ra_pages = 0; - req = ahash_request_alloc(vi->tree_params.hash_alg->tfm, GFP_NOFS); + req = ahash_request_alloc(params->hash_alg->tfm, GFP_NOFS); if (unlikely(!req)) { bio_for_each_segment_all(bv, bio, iter_all) SetPageError(bv->bv_page); return; } + if (bio->bi_opf & REQ_RAHEAD) { + /* + * If this bio is for data readahead, then we also do readahead + * of the first (largest) level of the Merkle tree. Namely, + * when a Merkle tree page is read, we also try to piggy-back on + * some additional pages -- up to 1/4 the number of data pages. + * + * This improves sequential read performance, as it greatly + * reduces the number of I/O requests made to the Merkle tree. + */ + bio_for_each_segment_all(bv, bio, iter_all) + max_ra_pages++; + max_ra_pages /= 4; + } + bio_for_each_segment_all(bv, bio, iter_all) { struct page *page = bv->bv_page; + unsigned long level0_index = page->index >> params->log_arity; + unsigned long level0_ra_pages = + min(max_ra_pages, params->level0_blocks - level0_index); - if (!PageError(page) && !verify_page(inode, vi, req, page)) + if (!PageError(page) && + !verify_page(inode, vi, req, page, level0_ra_pages)) SetPageError(page); } diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index 3b6b8ccebe7d..ecc604e61d61 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h @@ -77,6 +77,10 @@ struct fsverity_operations { * * @inode: the inode * @index: 0-based index of the page within the Merkle tree + * @num_ra_pages: The number of Merkle tree pages that should be + * prefetched starting at @index if the page at @index + * isn't already cached. Implementations may ignore this + * argument; it's only a performance optimization. * * This can be called at any time on an open verity file, as well as * between ->begin_enable_verity() and ->end_enable_verity(). It may be @@ -87,7 +91,8 @@ struct fsverity_operations { * Return: the page on success, ERR_PTR() on failure */ struct page *(*read_merkle_tree_page)(struct inode *inode, - pgoff_t index); + pgoff_t index, + unsigned long num_ra_pages); /** * Write a Merkle tree block to the given inode. |